Let me cut to the chase. There is no strong evidence suggesting pull rates or wonder pick chances increase when wishlisting Pokemon cards in Pokemon TCG Pocket.
Regardless, I put it to the test because I had nothing to lose.
What I did:
I was done pulling from the newest pack, so I decided to chase a full art Darkrai EX that I failed to pull during the Diagla / Pakia pack days. It could be by coincidence, however, I did pull that full art Darkrai EX after wishlisting it (see screenshot below).
It only took several days of pulling low-rarity cards on a dry streak. Then I finally pulled something worthy, a regular 4 diamond Diagla EX. Now, I’ve had good luck using my Pack Hourglass to pull additional cards when I got something like this on the first pull (either it be a 1-star card or a 4-diamond card), so I decided to use 24 Pack Hourglass for 2 additional pulls.
The first pull was a 3-diamond rarity card, so I decided to pull another (consuming the total of 24 Pack Hourglass). This is how I managed to pull the full art Darkrai EX. The only 2 star rainbow card I was missing from the Diagla pack, besides the full art Darkia EX, was Pachirisu EX.
So even if the algorithm does not give a secret boost or slightly higher priority for pulling your wishlisted cards, there’s no harm in adding them to your wishlist, just in case, especially since Wonder Pick highlights those cards in the Wonder Pick list.
